The present invention relates to an electrical connector, particularly (but not exclusively) to an electrical connector for use in telecommunications systems.
In the field of electrical connectors, it is usual to provide a form of strain relief for the cable to prevent or hinder accidental removal of the cable and to restrain the cable relative to contact members within the connector to maintain an adequate electrical contact. A known strain relief is shown in U.S. Pat. No. 5,030,136 in which flexible retaining tongues are formed within a cable passageway, the tongues serving to retain the cable therebetween, and being resiliently deformed upon insertion of the cable. The tongues extend inwardly towards each other from walls of the passageway and define a slot between them which is narrowest at its entrance and widens towards its root. They flex along the axis of the passageway when a cable is inserted.
This arrangement provides an adequate grip but is complex and difficult to manufacture. Accordingly, the cost of manufacture is increased and the likelihood of defective grips being produced is increased. As a result, the present invention seeks to provide a cable grip for a connector which is easier to manufacture and therefore incurs lower cost.
The present invention therefore provides a connector for an electrical cable, comprising a body in which is formed a passageway having a longitudinal axis, a contact element which projects into the passageway in order to make contact with the electrical cable when in the passageway, and a retaining element for hindering longitudinal withdrawal of the cable from the passageway, the retaining element comprising a pair of resiliently deformable lips extending into the passageway from a face thereof in a first direction transverse to the longitudinal direction, each of the lips being separated from a face of the passageway in a second direction transverse to both the first direction and the longitudinal axis, thereby to allow flexing of the lips in the second direction.
The lips are advantageously shorter than the depth in the first direction of the passageway. A particularly advantageous length is in the range 40 to 80% of the passageway depth. This eases the flexing of the lips to accommodate a cable. It also permits further lips to be provided on a lid which covers the passageway, the further lips extending in a direction opposed to the first lips. This means that a superior combination of flexing ability on the part of the lips can be combined with a grip for the cable around substantially its entire circumference.
The lips, when undeformed, meet or face each other at their adjacent edges. It is preferred that they are chamfered along those edges, ideally to a point. This allows the edge to grip the cable along a line, potentially deforming the insulation of the cable and providing a more secure grip. It is further preferred that the angle of chamfer increases along the length of the lip. Thus, it will be at a minimum at the base of the lips where they meet the passageway and will increase along the extent of the lips. This provides a physically robust lip which will therefore be reliable in service.
The lips can either meet at their adjacent edges, or a gap can be provided therebetween, depending on the intended wire gauge or range of wire gauges.